In a vehicle, a tire pressure detector may be used in conjunction with a Tire Pressure Monitoring System (TPMS) to measure air pressure in tires. Tires having low tire pressure may raise safety concerns and may also reduce operating efficiency of a vehicle. The tire pressure detector may be attached to a tire, or the wheel on which the tire is mounted, and may detect low tire pressure. Upon detection, the tire pressure detector may transmit this information to a vehicle operator via a TPMS or the like. The transmission of the tire pressure information is often performed wirelessly. For instance, a radio frequency transmission may be used to transmit tire pressure detector readings.
In a tire pressure detector, sensors in addition to a pressure sensor such as a temperature sensor and/or a speed sensor may be included. A battery also may be used to power components of the tire pressure detector. The tire pressure detector may also include communication components such as a phase locked loop (PLL) circuit, a crystal oscillator, an RF antenna that sends radio transmissions to a central control unit and possibly receives radio transmissions, etc. A power amplifier may also be included such that tire pressure signals may be amplified for transmission.
Traditional TPMS technology has developed several unique sensor designs for multiple different customers for such devices (e.g., different automobile manufacturers, etc.). Such an arrangement works well for supplying the particular customers with their components, but can lead to complications in the aftermarket. For example, when supplying spare parts to the aftermarket, such different designs require a retailer to stock multiple part numbers to be able to service all the different vehicle makes. For tire pressure detectors, for example, different information may be sent by a detector, and different frequencies may be used, based on the particular vehicle make and/or model. For example, common tire pressure detector designs use final transmitted frequencies of 315 MHz or 433.92 MHz, depending upon the particular vehicle make/model. Some replacement parts may allow for a tire pressure detector to be programmed by the retailer to provide appropriate information and data according to one of various different formats, thereby reducing the number of parts a retailer may have to stock. However, while the data that such a tire pressure detector transmits can be programmed, the frequency at which it transmits is fixed by the design of the electronics. Therefore, the retailer needs to buy and stock a 315 MHz sensor and a 433.92 MHz sensor.